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{{BlueBanner|The aim of this page is to centralize the RESOLUTION taken by the W3C Media Fragments Working Group while developing the Media Fragment 1.0 specification}} == Media Fragment Scope == * The WG resolved on [http://www.w3.org/2008/10/21-mediafrag-minutes.html#item04 2008/10/21] that the media fragment URI syntax will primarily use the '#' and consider using the '?' for other use cases (see also the [http://www.w3.org/2008/WebVideo/Fragments/wiki/Issues#URI_Fragment_.2F_URI_Query wiki page]) * The WG resolved on [http://www.w3.org/2008/10/21-mediafrag-minutes.html#item09 2008/10/21] to consider only rectangle shapes for the spatial dimension in a first version of the media fragment URI scheme * The WG resolved on [http://www.w3.org/2008/12/09-mediafrag-minutes.html#item02 2008/12/09] to provide either informally or in the specification a mapping between the media fragment URI scheme and the standards covered in the [http://www.w3.org/2008/WebVideo/Fragments/wiki/Existing_Technologies_Survey Technological Survey] * The WG resolved on [http://www.w3.org/2008/12/09-mediafrag-minutes.html#item03 2008/12/09] to consider four dimensions for addressing a fragment of a media resource, namely: time, space, track and name * The WG resolved on [http://www.w3.org/2008/12/09-mediafrag-minutes.html#item03 2008/12/09] that the track selection is limited to what the media container format is exposing * The WG resolved that the protocols covered by the media fragments URI scheme are HTTP and RTSP * The WG resolved on [http://www.w3.org/2009/09/17-mediafrag-minutes.html#item01 2009/09/17] that the aspect ratio is '''NOT''' considered as a fragment and therefore remove from the syntax and features offered by the Media Fragment URI specification == Media Fragment URI Syntax == See also the [http://www.w3.org/2008/WebVideo/Fragments/wiki/Syntax#Decisions decision on the syntax wiki page] * The WG resolved on [http://www.w3.org/2009/01/28-mediafrag-minutes.html#item02 2009/01/28] to use '&' as the primary separator in the media fragment syntax (see also the [http://www.w3.org/2002/09/wbs/42785/MFRAGSYNTAXSEPARATOR/results poll results]) * The WG resolved on [http://www.w3.org/2009/01/28-mediafrag-minutes.html#item02 2009/01/28] to use four schemes for defining a rectangle region and let the community decides (see also the [http://www.w3.org/2002/09/wbs/42785/MFRAGSYNTAXRECTANGLE/results poll results]) * The WG resolved on [http://www.w3.org/2009/01/28-mediafrag-minutes.html#item02 2009/01/28] that single quotes are optional to specify the value of the track and the name dimensions but that double quotes are forbidden (see also the [http://www.w3.org/2002/09/wbs/42785/MFRAGSYNTAXQUOTE/results poll results]) * The WG resolved on [http://lists.w3.org/Archives/Public/public-media-fragment/2009Mar/0039.html 2009/03/11] to use 'segment' as the top-production rule in the media fragment syntax (see also the [http://www.w3.org/2002/09/wbs/42785/MFRAGSYNTAXSEGMENT/results poll results]) * The WG resolved on [http://www.w3.org/2009/07/22-mediafrag-minutes.html#item03 2009/07/22] that the comma is optional for specifying a temporal Media Fragment and if a one is provided, this means it is the starting time * The WG resolved on [http://www.w3.org/2009/08/12-mediafrag-minutes.html 2009/08/12] to use the [http://lists.w3.org/Archives/Public/public-media-fragment/2009Jul/0038.html temporal-optional-comma specification syntax] proposed by Franck * The WG resolved on [http://www.w3.org/2009/09/02-mediafrag-minutes.html#item03 2009/09/02] that the syntax will '''NOT''' allow [http://lists.w3.org/Archives/Public/public-media-fragment/2009Jul/0018.html editUnits] for specifying the temporal dimension based on the [http://lists.w3.org/Archives/Public/public-media-fragment/2009Aug/0029.html following rationale] == Media Fragment Headers == * The WG resolved on [http://www.w3.org/2009/09/17-mediafrag-minutes.html#item02 2009/09/17] and in [http://www.w3.org/2009/09/23-mediafrag-minutes.html#item03 2009/09/23] for the clarification, that the syntax for expressing a Range request (using the HTTPBis clarification for having [http://tools.ietf.org/html/draft-ietf-httpbis-p5-range-07#section-5.4.2 custom units]), for the temporal dimension, is: Range: <dimension> ':' <unit> '=' <start-pos> - <end-pos> while the response will be: Content-Range: <dimension> ':' <unit> ' ' <real-start-pos> '-' <real-end-pos> '/' (<instance-length> / "*" ) == Test Cases == * Approval of [http://www.w3.org/2008/WebVideo/Fragments/wiki/TestCases#TC0000:_empty_MF TC0000] as per [http://www.w3.org/2009/05/13-mediafrag-minutes.html#item05 2009/5/13] * Approval of [http://www.w3.org/2008/WebVideo/Fragments/wiki/TestCases#TC0001:_undefined_time_segment_-_npt TC0001] as per [http://www.w3.org/2009/05/13-mediafrag-minutes.html#item05 2009/5/13] * Re TC0002-TC0007, the WG agrees that [http://www.w3.org/2009/05/13-mediafrag-minutes.html#item05 empty is not an error (as in 404) but a recoverable state] * WG agrees that [http://www.w3.org/2009/06/24-mediafrag-minutes.html#item04 empty representation means 416] * Approval of [http://www.w3.org/2008/WebVideo/Fragments/wiki/TestCases#TC0007:_base_multiple_segment TC0007] as per [http://www.w3.org/2009/06/24-mediafrag-minutes.html#item04 2009/6/24] * Approval of [http://www.w3.org/2008/WebVideo/Fragments/wiki/TestCases#TC0002:_empty_time_segment_-_npt TC0002] as per [http://www.w3.org/2009/08/12-mediafrag-minutes.html 2009/8/12] with 416, would yield an empty resource, hence client must have erred * Approval of [http://www.w3.org/2008/WebVideo/Fragments/wiki/TestCases#TC0003:_empty_space_segment TC0003] as per [http://www.w3.org/2009/08/12-mediafrag-minutes.html 2009/8/12] with 416, would yield an empty resource, hence client must have erred * Approval of [http://www.w3.org/2008/WebVideo/Fragments/wiki/TestCases#TC0004:_empty_space_segment_-_aspect TC0004] as per [http://www.w3.org/2009/08/12-mediafrag-minutes.html 2009/8/12] with 416, would yield an empty resource, hence client must have erred * Approval of [http://www.w3.org/2008/WebVideo/Fragments/wiki/TestCases#TC0005:_empty_track_segment TC0005] as per [http://www.w3.org/2009/08/12-mediafrag-minutes.html 2009/8/12], when changed to 200, the entire representation is returned * Approval of [http://www.w3.org/2008/WebVideo/Fragments/wiki/TestCases#TC0006:_empty_named_segment TC0006] as per [http://www.w3.org/2009/08/12-mediafrag-minutes.html 2009/8/12], when changed to 200, the entire representation is returned * Change and Approval of [http://www.w3.org/2008/WebVideo/Fragments/wiki/TestCases#TC0007:_base_multiple_segment TC0007] as per [http://www.w3.org/2009/08/12-mediafrag-minutes.html 2009/8/12], because #t=, now refers to the full resource; therefore return just named fragment * Add use cases as per [http://www.w3.org/2009/08/12-mediafrag-minutes.html 2009/8/12]: ** TC010: with #t=0,0&id='ID0' with 416, would yield an empty resource, hence client must have erred ** TC011: with #id='none' for non-existing id with 416, would yield an empty resource, hence client must have erred ** TC012: with #track='none' for non-existing track with 416, would yield an empty resource, hence client must have erred == Issues recorded in the tracker == === Combining Media Fragment URI with other time-clipping methods === Specifying a time-clipping method, for example in SMIL, is relative to the (timeline of the) resource. Therefore, if one specifies: <video clipBegin="5s" clipEnd="15s" src="http://www.example.com/video.mov#t=20,30"/> what's happen? The WG resolved on [http://www.w3.org/2009/02/04-mediafrag-minutes.html 2009/02/04] that in the cases where the media fragment is i) encompassing, ii) embedding, iii) disjoint or iv) partially overlapping the boundaries of another time-clipping method yield two possibilities: * EITHER the media fragment is regarded as out-of-context and the clipping method MUST be done relatively to the media fragment but bound to the media fragment, i.e. the UA plays the video segment between the seconds 25 (=max[20,20+5]) and 30 (=min[30,20+15]). * OR the media fragment is regarded as in-context and it depends on the application what the best solution is for the UA to do: some UAs may, for example, provide a timeline that encompasses the whole document, not only the time clipping. Implementors SHOULD follow semantics similar in spirit to the previous bullet, but adapted to their situation. See also the [http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/1 ISSUE-1] and the [http://www.w3.org/2008/WebVideo/Fragments/tracker/actions/37 ACTION-37] === What is the mime type of a media fragment? === The WG resolved on [http://lists.w3.org/Archives/Public/public-media-fragment/2009Feb/0052.html 2009/02/12] that the mime type of a media fragment is the *same* mime time of its parent resource. Hence, a media fragment addressing a single frame of a video would be of mime type video. If the media format constrains the playability of such resource (e.g. MP4 or 3GP explicitly forbid to have video with a zero duration), then the selection of this fragment will fail. In other words, media fragment URI are bound to the limitations of the underlying coding and container formats. See also the [http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/2 ISSUE-2] == Publication of Documents == * The WG resolved to publish [http://www.w3.org/2008/WebVideo/Fragments/WD-media-fragments-reqs/ Use cases and requirements for Media Fragments] as a FPWD on [http://www.w3.org/2009/04/16-mediafrag-minutes.html#item01 2009/04/16]

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